TPM for on-orbit satellite compute & frontier AI. PhD @UCBerkeley (astrophysics). šŖš¬ @penguinrandom author, Forbes 30u30, BRCA+. Astronomy/AI/ML.
San Francisco, CA
Joined August 2015
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Noor (ŁŁŲ±) Cassian Nielsen
Noor means light in Arabic. Cassian for courage, hope, and defiance.
Born at 6:01 PM on October 8, 2026
8lbs 8oz, 21.5 inches tall
The light of our lives, noor hayatuna š©µ. We love you more than this universe and all the rest, little guy. Canāt wait to experience the world through your eyes.
Delivering via scheduled C-Section exactly 1 WEEK from today and feeling ALL THE FEELS, especially as we kick off Breast Cancer Awareness Month.
I am so grateful we had the opportunity to perform genetic testing on our embryos to ensure my cancer-causing BRCA-2 mutation wasnāt passed onto my child.
I am so grateful for excellent formula options to be able to feed baby after I had a double mastectomy.
I am so grateful for the opportunity to remove my fallopian tubes when I deliver, reducing my risk of ovarian cancer.
And Iām so grateful for my bodyās resilience.
If youāre interested in supporting our next chapter, you can contribute to our postpartum meals š: giveinkind.com/inkinds/O2V0Yā¦
Today is National Previvor Day. A previvor is someone who has a genetic predisposition or high risk for developing cancerā someone like me.
I carry the BRCA-2 gene mutation, which I inherited from my dad. It puts me at high lifetime risk of breast cancer (87%), ovarian cancer (30%), and pancreatic and melanoma cancers.
I had a preventative double mastectomy to reduce my risk of breast cancer to <5%.
And now, Iām 9.5 months pregnant and delivering a baby boy next week. Get pregnant, I did IVF with preimplantation genetic testing to ensure my child wonāt also carry the mutation. And when I deliver next Friday, Iām having a C-Section so that we can remove my fallopian tubes at the same time.
This will reduce my risk of ovarian cancer.
In a decade or so, Iāll remove my ovaries. Iāll start enhanced screening protocols for pancreatic cancer, and Iāll continue to see a dermatologist every 6-12 months for melanoma screening.
All of this is incredibly difficult to navigate, but i STRONGLY believe that knowledge is power. Iām stronger for it.
Iāve been strength training and lifting 3x/week ~every week in pregnancy. 9 months later and I SWEAR it has saved my back and pelvis; im still dealing with aches and pains, but Iād be so much more uncomfortable had I not worked out this entire pregnancy.
Just 2.5 weeks to go!!!
Sarafina El-Badry Nance, PhD retweeted
The National Science Foundation (NSF) has issued a 10-page memo signaling a retreat from its traditional role of giving grants to individual researchers to pursue their best ideas and to train the next generation of scientists.
Instead, the memo makes clear, NSF will devote the bulk of its resources to addressing the research priorities of President Donald Trump and his administration, many of them technology focused. scim.ag/4ipE1kY
As a BRCA-2 carrier with a 30% lifetime risk of ovarian cancer, Iām getting my fallopian tubes out when I give birth (via C-section) in a couple of weeks.
So grateful options like this exist to reduce my risk. My grandmother had ovarian cancer 25 years ago and it was a devastating disease.
thank you so much to everyone who has contributed to our āmeal trainā - contributions here go straight toward warm meals during the fourth trimester and I cannot TELL YOU how grateful I am to have your support as we enter our next chapter! 3 weeks to go š„¹
giveinkind.com/inkinds/O2V0Yā¦
Sarafina El-Badry Nance, PhD retweeted
We Must Pace the Frontier: Iāve written a new essay on why the AI industry should slow down, with a three-part plan for doing so.
Anthropic is unilaterally committing to the first of these steps. Weāll provide third-party evaluators with permanent, employee-level access to our systems, so that they can verify adherence to our safety measures, report on incidents, and assess modelsā alignment during training.
You can read the full post here: darioamodei.com/post/we-mustā¦
Sarafina El-Badry Nance, PhD retweeted
Tristan Buckmaster's interview with Ken Chang @kchangnyt, with responses from @SebastienBubeck.
An N.Y.U. Mathematician Clashed With OpenAI Over a $1 Million Proof
nytimes.com/2026/09/10/scienā¦ via @NYTimes
A few days later, Iām at a team offsite in Sonoma, hot and exhausted. Weāre sitting at a table at a winery, and all of a sudden a golden retriever emerges from the tasting room and makes a BEELINE towards me. I am, ofc, thrilled. A few minutes later, Iām still petting the dog (duh) and his mom comes out of the tasting room carrying the book in the second photo, WINE DOGS. She walks up and hands me the book, saying āThis is for you to read with your baby on the long postpartum nights aheadā. Again - I cried. TEARS!!!! Turns out she saw what a big dog person I am and knew Iād appreciate stories of all the dogs across California wine country. She happens to be a professor at UC Berkeley, and we connected on LinkedIn. Again - the universe. š„¹
The third is a great big thank you to everyone who has contributed to postpartum meals for Taylor and I ā nearly $1K š. My favorite thing about pregnancy (even though I hate most of it lol) is that it brings humanity, love, empathy, and care to the surface. Iām ASTONISHED by the kindness given to us by our community and this is just a small example of it. I strongly believe that life moments like this are meant to be shared - in all their joy and pain!
Thank you for making this chapter of our lives easier. Thank you for sharing in our love ā¤ļø
giveinkind.com/inkinds/O2V0Yā¦
Some stories of incredible generosity from the annals of being 8 months pregnant.
One Saturday evening, we were out for dinner and spotted a woman waiting for a table and holding this book. We started chatting ā turns out, her dad was visiting and brought her a copy because he used to read it to her every single night when she was a baby. Of COURSE I was so touched and loved hearing about their special bond.
An hour later, Iām eating dinner at our table and she and her dad come up to me. They hand me the book, saying āIt was meant to beā for us to meet and for me to read this copy to my baby. I cried, and we hugged, and I promised to send photos of us reading together. In that moment, it felt like the universe reached towards us and gave us all a hug.
